Figure 4

Phospho-histone H3 distribution on chromatin of unfertilized wildtype and YA-deficient eggs. Immunostaining of 0–15 minute old laid unfertilized wildtype and Ya² eggs (from Oregon R P2 and X^X Ya²/Y mothers, respectively). DNA shown in red, phospho-histone H3 (PH3) in green. A-C are projections of multiple confocal images. (A) Four decondensed wildtype nuclei in promeiotic interphase or S phase, with PH3 excluded from nuclei (any faint PH3 staining was around the nuclear periphery). (B) Four condensed wildtype meiotic products perpendicular to the egg cortex, with PH3 staining on all chromatin. (C) Condensed Ya² meiotic products (probably 1:1:2, post meiotic but just after telophase since still arranged linearly), with PH3 staining on all chromatin. (D) Four Ya² meiotic products in two planes; three grouped at the egg cortex and one deeper in (inset). Although all four nuclei have similar nuclear areas, and thus are likely all haploid, only one of the three haploid nuclei at the cortex forming the polar body has individualized chromosomes with PH3 staining. Arrowheads indicate decondensed nuclei without PH3 staining. Wildtype n = 64 eggs. Ya² n = 20 eggs. Bar = 10 μm.